A fishy problem.

[puka777]

ok then from that information i m going to have to say ammonia burn. if your tank filter has been taken out for more then 24 hours then all good bacteria which breaks down ammonia has died off.
so basically by taking out the filter and the fish not having a filter you fish is basiclly swiming in toxins. or you could say its like a human swiming in their own waste.

im not sure what you should i know that you now have to start whats known as the nitrogen cycle which is the growth on good bacteria in the filter which breaks down ammonia into nitrite then nitrite into nirate which can be taken out by water changes.
visit the website now they hopefully help you with the midcation you have to give the fish.

 

[Brianna]

I'm pretty sure that there is something in SA rainwater that makes it unsuitable for aquarium use.

Just because NSW rainwater is okay, doesn't mean that SA rainwater is necessarily okay..

Not that it means that that is what has caused the problem anyway.

Anyhoo, hope your fishy gets better!

 

[Ristof]

I have found that rain water in Vic will not kill the fish but you need to add a lot of things into it to get it upto a standard that is suited more for fish. ie - hardness, PH.
If you have a concret water tank then the PH could be high which doesn't help removel of ammonia
I use town water and the PH is 7.0 and the hardness is about 100GH so all I need to add in is a conditioner.
Being a 2ft tank and the amount of water in there means that if you do get a problem the problem can spread very quickly, to say a 3 to 6ft tank.
She could be stressed being at the back with the males in the front
How is she going being by herself in another tank
I have a 4ft tank that I haven't cleaned for about 5mths, running a canister filter. all I do is the occational top up when the water level drops.
The turtles I have are the same

 

[yolbit]

i have seen this problem with my tropical fish before...

if its fins are discoloured white with stringy bits coming that is an indicator of a bad pH levels in the water

im not sure what the optimum pH is for fighters but most fish are happy between 6.5 and 7. also keep in mind that the pH scale works logarithmically, in that a pH of 6 is ten times more acidic as a pH of 7, which is 100 times as acidic as 8 and so on... so getting your pH as close as posible with tropical fish is very important

 

[bk201]

lol cudnt be bothered reading all the posts so if i dont make sense dont worry
for fin rot i would recomend aqua master tri-sulfa tablets but the asians who breed and raise thousands of fighters use indian almond leaves in with theres to control fin problems and such and to prevent diseases, with anyfish it it best to do a maximum of like 30% water change at a time especially with fighters since there tropical fish.also some people say ffighters r from bad conditions so u can keep them in dirty water this is not the case

also it would be a good idea to google tropical fish diseases or fin rot and you might find some accurate answers solutions and pics to identify the problem not just random speculations by people such as me

hope this helps if it doesnt ignore me , i havnt slept in 50 hours so im not sure if im making sense:|